1. Field of the Invention
This invention relates to the placement or replacement of restraining bale ties on bundles or bales of compressible solid material. Particular application exists with regard to the recompression of cotton bales to higher densities or the repair of cotton bales that have been damaged due to the loss or improper functioning of one or more bale ties.
2. Description of the Prior Art
Presently, approximately 85 million bales of cotton are produced worldwide with 18 to 20 million bales produced in the United States annually, each weighing about 500 pounds. In the United States they are formed in the typical cotton gin at the rate of one every 2 to 4 minutes. This is done by having the cotton fiber fed down an inclined plane into a preliminary tramping mechanism which forces the cotton into a typically rectangular enclosure. Once this enclosure contains the desired amount of cotton, it is then rotated to a second position where considerable compressive force is applied for baling.
Most gin presses have two rectangular enclosures, one to store cotton during ginning and the other to do the actual compression. The cotton bale is formed by its compression between a pair of 20xc3x9754-inch rectangular plates, or platens, to which a force ranging from about 150,000 to about 1,000,000 pounds is applied. The platens conventionally have six to eight groves therein that are about one-inch wide and two inches deep. These facilitate the insertion of bale ties once the bale is compressed to a density of about 42 pounds per cubic foot, which corresponds to a thickness of about 19 to 20 inches. These bale ties, typically comprising of round steel wires or flat straps made of steel or polyester, are then made to encircle the bale and their loose ends connected together. The compressive mechanism is then released and the bales are allowed to expand to a thickness that the restraining bale ties permit, this conventionally ranges from about 26 to 32 inches. Final bale dimensions are thus typically about 21 inches by 55 inches by 26 to 32 inches.
Compression to high densities requires large forces and. extensive mechanical and hydraulic systems which may not be economical for some gin operations. Mechanisms to achieve secondary compression from low to high density are unavailable.
Bale tie failures, caused by such factors as improper tie-off, improper matching of bale ties to compression density, uneven cotton distribution within the bale, low moisture content, defective ties, and improper storage or handling, are significant problems which plague the cotton industry. While specific statistics are not kept on the number of bale tie failures during a typical year, it is estimated that about 4% or over 800,000 bales, experience tie failures annually. Bale tie failure rates in excess of 10% annually have, however, been reported at some storage facilities. Typically, from one to four ties break in a given bale, thereby allowing it to expand from its original thickness of 26 to 32 inches up to about 38 to 42 inches. Bales damaged through loss of bale ties are rejected by mill customers due to their increased susceptibility to contamination and their loss of physical conformity to the mill""s processing machinery.
Repair procedures in the past have included such approaches as recompression of the entire bale in conventional baling equipment or manually cinching a replacement tie around the bale. The deficits in these approaches are that use of the baling equipment requires that the gin not be processing cotton at the time, the bale expands to dimensions greater than the press opening and the bale must be completely unpackaged, and manual cinching may fail to adequately reconstrain the bale.
Warehouses handling cotton bales have been compelled, as a result of this situation, to dedicate expensive, large-scale bale presses for accomplishing bale tie replacement. Smaller gins and warehouses having insufficient bale tie failures to justify the major expenditures for a bale press must ship the defective bales to a gin or similar facility for repair at significant cost in order to make them acceptable for market. Aside from transportation, repair costs range from $10 to $45 per bale, depending on the availability of a bale press. This works out to a cost of $8 to $36 million for repairing of the 800,000 bales damaged annually.
U.S. Pat. No. 4,438,689 to Simich teaches a method to apply wires to a material baling device which comprises a pair of wide platens, each containing at least one recessed channel for use with placement of bale tie wires. The device includes a power feed assembly designed to guide the bale tie wires through the platen channels so that their placement and securing is made less labor intensive.
U.S. Pat. No. 4,509,416 to Simich teaches bale tie joining devices for securing bale tie ends on the top of the bale, wherein the completed tie joint or knot is readily visible to the press operator from the top prior to bale release.
U.S. Pat. No. 5,921,174 to Anthony teaches a method to replace broken bale ties which consists of inserting a portion of a bale lengthwise into a press, compressing a bale of cotton in a narrow area, emplacing a single bale tie, releasing the bale, and repeating the process.
The shortcomings of prior machines and methods for compressing bales and/or repairing bale tie failures are addressed and essentially minimized through the use of the device and methodology provided by the present invention. The device includes a base frame structure which is sufficiently compact so as to be readily transportable but large enough to accept an entire bale at it""s widest dimension. The device further includes a platen base having transversely attached thereto one or more elongated platens, similar to those disclosed by Anthony in U.S. Pat. No. 5,921,174, issued Jul. 13, 1999; hereby incorporated by reference. These platens are affixed in a manner to allow them to be reversibly maintained above the platen base by tension means until such time as bale compression is initiated. Platens positioned in areas of desired compression are selectively xe2x80x9clockedxe2x80x9d in this extended conformation, while those at points where there is no desire to apply pressure, are allowed during operation to compressibly recede into the base platen. The device further includes an upper compressive platen that may be brought into aligned opposition with a selected lower platen and capable of movement toward and away from said opposed platen for purposes of applying a localized compressive force only in that area where a bale tie is to be attached.
In accordance with the invention, the platens are positioned for compressing a damaged bale therebetween by movement within the same plane toward one another. The compression surfaces of the platens each have a cross-sectional dimension in a direction perpendicular to the major axis thereof, which is sufficiently small so as to allow compression of a bale only in close proximity to the location on the bale where a bale tie is intended to be placed. The device further includes a drive mechanism that is mechanically coupled to the platens and is operable to move the platens relatively toward one another.
In accordance with a preferred form of the invention, a longitudinally extending bale tie receiving recess may be provided in at least one of the opposing platen compression surfaces. Advantageously, a longitudinally extending bale tie receiving recess may be provided in both of the opposing platen compression surfaces.
In a further embodiment of the present invention, one of the platen bases contains multiple platens spaced so as to span the length of the bale, each of which are supported above the platen base by compressible springs, reversibly deformable materials such as rubber, hydraulics or similar means that are sufficiently strong to withstand the weight of a bale without appreciable deflection.
In yet another embodiment of the present invention, a locking means is associated with each recessible platen so as to selectively prevent it from receding into the platen base when compressive forces are applied, thereby allowing all the available force to be applied specifically in the desired area.
In accordance with yet another embodiment of the instant invention, the tension means acting for the extension of each recessible platen is such that the platen will extend beyond the contact face of the platen base as compressive force is removed, thereby allowing the reversible xe2x80x9clockingxe2x80x9d of alternate platens for compressible contact with a bale.
In accordance with the invention, the drive mechanism may include one or more cylinder assemblies operable by any art known means including mechanical, hydraulic or pneumatic. This drive mechanism may, in the alternative, include one or more manually operated jacks.
In another form of the invention, the longitudinally extending bale contacting and compressing surfaces of the platens may be triangular in cross-section and present a v-shaped nose portion disposed to point toward a bale. Such a conformation concentrates and localizes the compression forces applied during the repair operation.
The device of the invention may also include a conveyor apparatus situated beside the base frame structure. Such a conveyor apparatus may be disposed so as to transport a damaged bale to a repair zone located between the platens.
The invention also provides a method for repairing bales which have been damaged as a result of bale tie failure. The method includes placing a damaged bale in a repair zone and thereafter compressing the damaged bale only in the area proximate to the positions where a bale tie is to be placed and, while the bale is compressed, installing the needed bale ties around the bale.
The device for compressing cotton bales in accordance with the invention provides a means for repairing defective bales of cotton on site and of further compressing bales without need for movement of the bale for repair of multiple ties. Only a single operator is required for a period of about 5 to 15 minutes to replace up to eight defective ties. This compares very favorably with known procedures and devices where as many as four operators are required for thirty minutes, using a full size baling press that currently markets for more than $300,000. The cost of the automatic device of the present invention, due to reduced energy and equipment requirements may be only about $40,000.
In accordance with the invention, repair may be accomplished without interruption of the ginning or warehouse operations. Repair may also be accomplished at a warehouse or textile mill where no bale press is available. Since bales from several gins are often consolidated at a central warehouse, repair may be accomplished at such a warehouse without interruption of the normal operations.
As will readily be recognized by those of ordinary skill in the art to which the present invention pertains, the device may be readily adapted for transport.
In accordance with the invention, the device for installing bale ties is intended to meet the needs of the individual cotton gin or warehouse.